I lowered the two pillars to rewrite Sinestro's story, but the game was not registering it. What I did was: I got the rune from the left and placed it on the right pillar, then I got the rune from the right, and placed it on the left pillar - repeat. I had to return to character selection screen (it placed me back in Mogo, I was there before going to Mournful Mogo), then entered the Cave again. I did things differently: completed one pillar before starting the other. You also might look into the waves that arrive from the entrance. I didn't notice most of them at first, and I wonder if I might have ignored one of them and that bugged the instance. Finally, counting the 2 pillars as one single objective might be a mistake. Make it (0/2) so we can keep track of our progress - because I have absolutely no idea if both of the pillars bugged for me on the try or if it was just one of them. (I'd be happy to test future DLCs, It seems like you guys can use some help in that department.)
The (0/2) sounds like a good idea tbh. I also wish it'd mark on the minimap or give you an arrow where to go when you have the symbol, but maybe not having that allows you to figure it out for yourself which is also fun. I also had the issue when I was kicked that it put me back in the spot in the zone I was in before I went to Mournful Mogo
